When you're having vaginal or anal sex with your partner in the full nelson position, and right before you're gonna bust a nut, deliver a single, powerful thrust that launches them in mid-air and as they're coming back down, proceed to deck them right in the kisser.
My wife and I recently divorced because I decided to treat her to something special in the bedroom one night, and in the heat of the moment right when I was about to nut, I delivered the Harlem Haymaker hard enough that, not only did she clench like a vice grip, but also went into a 2-year coma.